Silver halide photographic photosensitive materials of high picture quality which can be subjected to rapid processing have become desirable in this field in recent years.
Development processing of silver halide photographic photosensitive materials is generally carried out continuously in automatic processors which have been installed in processing laboratories. As part of the user service it is now generally required that the material be processed and returned to the user on the same day that it is submitted for development. More recently a demand has also arisen for return within 1 hour of receipt. As a result, the necessity for rapid processing becomes ever more pronounced. Moreover, a shortening of processing time improves production efficiency and allows costs to be cut so great progress has been made with rapid processing.
The form, size and composition of silver halide gains in emulsions used in the photosensitive materials is known to have a considerable effect upon the rate of development under these circumstances. For example, the halogen composition has a pronounced effect, and especially high rates of development can be observed when silver halides which have a high chloride content are used.
Furthermore, it has become desirable not to include benzyl alcohol in color development baths in recent years from the viewpoints of environmental protection and reducing the operational burden of preparing color development solutions. Furthermore, sulphites which have been used as antioxidants for developing agents, etc., in color development solutions, reacts with couplers competitively with the oxidized product of the color developing agents, thus lowering the image density. The colored dye densities change if the amount of sulfite present in the color development solution changes. Therefore, the omission of sulfite from the color development solution is also desirable.
Against this background, high chloride silver halides have recently been used for color papers. Also, methods of processing with color developers which are essentially benzyl alcohol and sulfite free have come into practical use.
However, color mixing is liable to occur when high chloride silver halides are used. It is believed that because of the very high rate of silver development, the proportion of the oxidized product of developing agent produced by silver development which diffuse into other layers rather than reacting with the couplers in the layer in which it is formed is increased relative to that which occurs with slow silver development. Furthermore this phenomenon is promoted with the aforementioned color developers which contain no benzyl alcohol or sulfite.
Increasing the thickness of the intermediate layers which are located between the emulsion layers and increasing the amount of anti-color mixing agent are ways of resolving this problem, but a considerable increase is required to improve color mixing to a satisfactory level. Also, the cost is high, and the rapidity of processing is reduced by increasing the film thickness.